Design and Fabrication of Radio Controlled Car
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International Journal of Mechanical Engineering and Technology (IJMET) Volume 6, Issue 8, Aug 2015, pp. 01-11, Article ID: IJMET_06_08_001 Available online at http://iaeme.com/Home/issue/IJMET?Volume=6&Issue=8 ISSN Print: 0976-6340 and ISSN Online: 0976-6359 © IAEME Publication ___________________________________________________________________________ DESIGN AND FABRICATION OF RADIO CONTROLLED CAR Keshav Jha, Sai Phanindra Dinesh Kakarlamudi, Bharath Konduru, Mukesh Reddy Vadala, Shravani Rallapati, Sonu Gupta and Chanikya Virugadinla Department of Mechanical Engineering, JNTUH College of Engineering, Kukatpally, Hyderabad, 500085 ABSTRACT Radio controlled (or R/C) cars are battery/gas-powered model cars or trucks that can be controlled from a distance using a specialized transmitter or remote. This Radio controlled system is adopted in many vehicles like cars, boats, planes, and even helicopters and scale railway locomotives. Different types of radio controlled cars like Gasoline, nitro-methanol and electric cars exist, which are designed to be run both on and off-road. "Gas" cars traditionally use petrol (gasoline), though many hobbyists run 'nitro' cars, using a mixture of methanol, nitro methane and oil, to get their power. Among these nitro cars, there exists different types of models based on scales like 1/8 off road nitro buggy, 1/16 nitro-t Truggy, 1/16 nitro racing buggy, 1/10 nitro buggy cars etc. Mostly these car are used for participating in racing competitions held in different college technical fests with the event names like MINI-GP, GRAND PRIX, FIRE AND ICE etc. Here, we have designed and fabricated a 1/8 off road nitro buggy car to participate in the MINI GP event OF BITS Hyderabad technical fest, FIRE and ICE event of IIT Madras technical fest and in many more competitions. The design and structural analysis of the NITRO BUGGY CAR was done by using SOLID WORKS software. After the successful design of the car, it was set for fabrication where chassis, steering arms, shock towers etc were fabricated. Finally, after fabrication and assembly, the car was set to run. Key words: Cars, Design, Fabrication, Nitro Buggy Car, Radio Controlled. Cite this Article: Keshav Jha, Sai Phanindra Dinesh Kakarlamudi, Bharath Konduru, Mukesh Reddy Vadala, Shravani Rallapati, Sonu Gupta and Chanikya Virugadinla, Design and Fabrication of Radio Controlled Car. International Journal of Mechanical Engineering and Technology, 6(8), 2015, pp. 01-11. http://iaeme.com/Home/issue/IJMET?Volume=6&Issue=8 _______________________________________________________________ http://iaeme.com/Home/journal/IJMET 1 [email protected] Keshav Jha, Sai Phanindra Dinesh Kakarlamudi, Bharath Konduru, Mukesh Reddy Vadala, Shravani Rallapati, Sonu Gupta and Chanikya Virugadinla 1. INTRODUCTION Radio controlled (or R/C) cars are battery/gas-powered model cars that can be controlled from a distance using a specialized transmitter or remote. The term "R/C" has been used to mean both "remote controlled" and "radio controlled", where "remote controlled" includes vehicles that are connected to their controller by a wire, but common use of "R/C" today usually refers to vehicles controlled by a radio- frequency link. This article focuses on radio-controlled vehicles only. Most fuel- powered models use glow plug engines, small internal combustion engines fueled by a special mixture of nitro methane, methanol, and oil (in most cases a blend of castor oil and synthetic oil). These are referred to as "nitro" cars. Recently, exceptionally large models have been introduced that are powered by small gasoline engines, similar to string trimmer motors, which use a mix of oil and gasoline. Figure1 R/C Nitro Buggy Car 2. PRINCIPLE OF OPERATION Transmitters send radio waves or electromagnetic frequencies to an RC car or other remote controlled device. The operator moves the controls on his remote control radio. The transmitter talks to the receiver via the radio carrier wave. The receiver can be a circuit board with internal antennas or a larger antenna on the exterior of the remote controlled car. Any radio signals coming from the transmitter end up at the receiver. The receiver then converts these signals for the servo motor. The receiver transforms all radio signal broadcasts received from the transmitter into the suitable electronic signals that are required for all other components within the control system. Many of the available systems apply the amplitude modulation for the radio signals, and then they encode positions using pulse width modulation. The radio is wired up to either electronic speed controls or servomechanisms which perform actions such as throttle control, braking, steering, and on some cars, engaging either forward or reverse gears. Electronic speed controls and servos are commanded by the receiver through pulse width modulation; pulse duration sets either the amount of current that an electronic speed control allows flowing into the electric motor or sets the angle of the servo. On the models the servo is attached to at least the steering mechanism, rotation of the servo is mechanically changed into a force which steers the wheels on the model, generally through adjustable turnbuckle linkages. Fuel powered models utilize a servo for throttle and braking control; rotation of the servo in one direction http://iaeme.com/Home/journal/IJMET 2 [email protected] Design and Fabrication of Radio Controlled Car will cause the throttle on the carburetor to open, providing more air and fuel mixture to the internal combustion engine. Rotation of the servo in the other direction causes torque to be applied to a piece which causes friction with the braking material. 3. PARTS INVOLVED IN THE CAR 3.1. ENGINE A small internal combustion engine is typically used in model aircraft, model cars. NITRO Engine: A nitro engine generally refers to an engine powered with a fuel that contains some portion (usually between 10% and 40%) of nitro methane mixed with methanol. Nitro methane is a highly combustible substance that is generally only used in very specifically designed engines, and is primarily used almost entirely by itself in certain of automotive drag racing. Most gas R/C models use a 2- or 4-stroke glow engine, sized specifically for that model. Most glow engines have a simple ignition system that uses a glow plug rather than a spark plug so there's no coil, magneto or points. The glow plug is heated by a battery operated glow starter. When fuel enters the combustion chamber, it's ignited by the heated glow plug and with that, the engine springs to life, instantly gaining the momentum to continue running after all the starter accessories are removed. The engine's carburetor supplies the fuel and air needed for combustion. Figure 2 Nitro Engine Parts Figure 3 Nitro Engine 3.2. Chassis The rectangular, usually aluminum or carbon graphite frame, supported on springs and attached to the axles, that holds the body and motor of a radio controlled car. The chassis should be light in weight; strong and also able hold all the body components. 3.3. Control systems: (Receiver and Transmitter) Radio control system is required to control the I.C. engine car. Throttle and steering are both taken car by a Remote Control set which consists of a receiver, transmitter and servo motor. 3.3.1. Receiver: The receiver is a small rectangular device mounted on the car. It has a wire (usually 19") that acts as an antenna to receive signals from the transmitter. Nitro cars need a 3-channel radio control system. 2-channels for the 2 servos connected to the receiver and the third channel is connected to the battery as the receiver needs a 6-volt supply to run. http://iaeme.com/Home/journal/IJMET 3 [email protected] Keshav Jha, Sai Phanindra Dinesh Kakarlamudi, Bharath Konduru, Mukesh Reddy Vadala, Shravani Rallapati, Sonu Gupta and Chanikya Virugadinla 3.3.2. Transmitter: The transmitter is the controller. Transmitters have control sticks, triggers, switches, and dials at the user's finger tips. The stick type used two "sticks". The left stick is used to control the speed of the car, and the right stick is used to steer the car. The pistol type uses a "trigger" and a steering wheel. The trigger is used to control the speed of the car, the wheel to steer the car. 3.4 Servos A servo normally has a plastic outer body with a small but very powerful electric motor and gearbox inside. The servo’s gearbox consists of a set of plastic or metal gears.. A nitro car has 2 servos, 1 is connected to the throttle and brake and the other is connected to the steering assembly of the car. The servo connected to the carburetor controls the speed of the car. It also controls the braking mechanism. The second servo is connected to the steering mechanism, controlling the direction of the car's front wheels. They all have the standard three pin connectors, with ground (black), +4.8 to 7.4V voltage (red), and signal (white). 3.5. Batteries and battery charger The most common chemistries for RC applications are NiMH or NiCd and Lithium Polymer batteries. The ratings on batteries are: mAh or Ah, S and P, C. There are different types of battery chargers like slow charger, fast charger, lithium charger and filed chargers. 3.6. Igniter A rechargeable Glow plug igniter is required to start a Nitro Engine. We should always use a rechargeable version as it gives a much better glow. 3.7. Fuel tank Fuel tank is a box like tank in r/c car where fuel is kept. A 125cc fuel tank with open capacity plug is used. 3.8. Carburetor Nitro engines typically use a carburetor to mix the fuel and air together, although for some applications where throttling is not required they have a simple venture with a spray bar and needle valve.